My 06 HSE has 90K miles and I feel the same way. I have replaced the sway bar links front and rear, which helped but didn't resolve the issue. If I were to sum it up, I'd say that every road imperfection, bump and swale unsettles the car more than it should, for longer afterwards than it should.
I think there are two possibilities:
1 Shocks inside air spring are no longer damping the suspension movements, or
2 The valve blocks have leaks internally, allowing pressurized air to move within the spring system from left to right and front to back - basically crosslinking - reducing spring rate of the spring(s) with highest load. If I imagine driving the truck on-road with the crosslink valves opened, I can see how this fits as a source of issue.
Air springs are expensive, so I guess the proper strategy is to investigate the valve blocks as issues first, and see what happens there.
I think there are two possibilities:
1 Shocks inside air spring are no longer damping the suspension movements, or
2 The valve blocks have leaks internally, allowing pressurized air to move within the spring system from left to right and front to back - basically crosslinking - reducing spring rate of the spring(s) with highest load. If I imagine driving the truck on-road with the crosslink valves opened, I can see how this fits as a source of issue.
Air springs are expensive, so I guess the proper strategy is to investigate the valve blocks as issues first, and see what happens there.
